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Clinically validated, automated arm-cuff blood pressure measuring devices (BPMDs) are recommended for BP measurement. However, most BPMDs available for purchase by consumers globally are not properly validated. This is a problem because non-validated BPMDs are less accurate and precise than validated ones, and therefore if used clinically could lead to misdiagnosis and mismanagement of BP. In response to this problem, several validated device lists have been developed, which can be used by clinicians and consumers to identify devices that have passed clinical validation testing. The purpose of this review is to describe the resources that are available for finding validated BPMDs in different world regions, to identify the differences between validated device lists, and describe current gaps and challenges. How to use validated BPMDs properly is also summarised. ispartof: JOURNAL OF HUMAN HYPERTENSION vol:37 issue:2 ispartof: location:England status: Published online

Clinically validated, automated arm-cuff blood pressure measuring devices (BPMDs) are recommended for BP measurement. However, most BPMDs available for purchase by consumers globally are not properly validated. This is a problem because non-validated BPMDs are less accurate and precise than validated ones, and therefore if used clinically could lead to misdiagnosis and mismanagement of BP. In response to this problem, several validated device lists have been developed, which can be used by clinicians and consumers to identify devices that have passed clinical validation testing. The purpose of this review is to describe the resources that are available for finding validated BPMDs in different world regions, to identify the differences between validated device lists, and describe current gaps and challenges. How to use validated BPMDs properly is also summarised.

Objective The objective of this study was to determine the accuracy of the oscillometric blood pressure measurement technology of the Novacor Diasys 3 (model number DIS-0001-00) blood pressure monitor, intended for ambulatory blood pressure measurement, when used with the recommended Standard (ACC-0213-00), Large (ACC-0214-00) and Paediatric (ACC-0215-00) cuffs. Methods The Novacor Diasys 3 (model number DIS-0001-00) was evaluated according to the requirements of the AAMI/ANSI/ISO 81060-2:2013 standard, including an additional cardiac-stress study, a requirement for ambulatory blood pressure measurement devices. It was also validated according to the requirements of the European Society of Hypertension International Protocol revision 2010. The protocol requirements for all thee studies were followed precisely. Results The Novacor Diasys 3 (model number DIS-0001-00) fulfilled all of the requirements for a pass in each of the three studies. In the primary AAMI/ANSI/ISO 81060-2:2013 study, the Criterion 1 errors were +3.9 mmHg ± 2.9 mmHg for SBP and +3.4 ± 2.5 mmHg for DBP. Conclusion The Novacor Diasys 3 (model number DIS-0001-00), when used with the recommended cuffs, can be recommended for ambulatory blood pressure measurement in the adult population.

Digital, The Lancet Commission on Hypertension identified that a key action to address the worldwide burden of high blood pressure (BP) was to improve the quality of BP measurements by using BP devices that have been validated for accuracy. Currently, there are over 3 000 commercially available BP devices, but many do not have published data on accuracy testing according to established scientific standards. This problem is enabled through weak or absent regulations that allow clearance of devices for commercial use without formal validation. In addition, new BP technologies have emerged (e.g. cuffless sensors) for which there is no scientific consensus regarding BP measurement accuracy standards. Altogether, these issues contribute to the widespread availability of clinic and home BP devices with limited or uncertain accuracy, leading to inappropriate hypertension diagnosis, management and drug treatment on a global scale. The most significant problems relating to the accuracy of BP devices can be resolved by the regulatory requirement for mandatory independent validation of BP devices according to the universally-accepted International Organization for Standardization Standard. This is a primary recommendation for which there is an urgent international need. Other key recommendations are development of validation standards specifically for new BP technologies and online lists of accurate devices that are accessible to consumers and health professionals. Recommendations are aligned with WHO policies on medical devices and universal healthcare. Adherence to recommendations would increase the global availability of accurate BP devices and result in better diagnosis and treatment of hypertension, thus decreasing the worldwide burden from high BP., La Comisión Lancet de Hipertensión determinó que una medida clave para responder a la carga mundial que representa la hipertensión arterial era mejorar la calidad de las mediciones de la presión arterial, mediante la utilización de dispositivos cuya exactitud haya sido validada. En la actualidad existen 3000 dispositivos comercializados, pero muchos no tienen datos publicados sobre pruebas de exactitud conformes a las normas científicas establecidas. La falta de regulación o su ineficiencia, que permiten la autorización de dispositivos para uso comercial sin una validación oficial, posibilitan este problema. Además, han surgido tecnologías nuevas de medición de la presión arterial (por ejemplo, los sensores sin brazalete) sobre las cuales no existe unanimidad en la comunidad científica con respecto a las normas de exactitud de la medición. En conjunto, estos aspectos contribuyen a la disponibilidad generalizada de tensiómetros de consultorio o domiciliarios que ofrecen una exactitud limitada o incierta, que llevan a diagnósticos, manejo y farmacoterapia inapropiados de la hipertensión a escala mundial. Los problemas más importantes relacionados con la exactitud de los dispositivos de medición de la presión arterial se pueden resolver mediante el requisito regulatorio de una validación independiente obligatoria de los dispositivos, en consonancia con la norma ISO universalmente aceptada. Esta es una recomendación básica y constituye una necesidad internacional acuciante. Otras recomendaciones clave son la elaboración de normas de validación específicas para las tecnologías nuevas de medición de la presión arterial y la publicación en línea de listas de los dispositivos nuevos exactos que están a la disposición de los usuarios y los profesionales de salud. Las recomendaciones están en consonancia con las políticas de la Organización Mundial de la Salud sobre los dispositivos médicos y la atención universal de la salud. El cumplimiento de las recomendaciones aumentará la disponibilidad mundial de dispositivos de medición de la presión arterial que sean exactos y tendrá como efecto un mejor diagnóstico y tratamiento, reduciendo así la carga mundial de la hipertensión., A Comissão Lancet sobre Hipertensão Arterial identificou que uma iniciativa central para enfrentar a carga mundial da hipertensão arterial seria a melhoria na qualidade da mensuração da pressão arterial pelo uso aparelhos de pressão arterial validados quanto à acurácia. Atualmente, existem mais de 3 000 aparelhos de pressão arterial disponíveis comercialmente; entretanto, muitos não têm dados publicados sobre testes de acurácia realizados de acordo com padrões científicos estabelecidos. Este problema resulta de regulamentação fraca ou inexistente, o que permite a aprovação para uso comercial de dispositivos sem validação formal. Além disso, surgiram novas tecnologias de mensuração da pressão arterial (por exemplo, sensores sem algemas) sem consenso científico quanto aos padrões de acurácia. No conjunto, essas questões contribuem para a oferta generalizada de dispositivos de pressão arterial clínica e domiciliar com acurácia limitada ou incerta, levando a diagnóstico, gerenciamento e tratamento inadequados da hipertensão em escala global. Os problemas mais significativos relacionados com a acurácia dos dispositivos de pressão arterial podem ser resolvidos por regulamentação que imponha a obrigatoriedade de validação independente dos aparelhos de pressão arterial, de acordo com a norma universalmente aceita pela Organização Internacional de Normalização. Esta é uma recomendação fundamental para a qual existe uma necessidade internacional urgente. Outras recomendações essenciais incluem o desenvolvimento de padrões de validação especificamente para novas tecnologias de mensuração da pressão arterial e listas on-line de aparelhos com acurácia adequada que sejam acessíveis aos consumidores e profissionais de saúde. As recomendações estão alinhadas com as políticas da Organização Mundial da Saúde (OMS) sobre dispositivos médicos e atenção universal à saúde. A adesão às recomendações aumentaria a oferta global de dispositivos de pressão arterial com acurácia adequada e resultaria em melhor diagnóstico e tratamento da hipertensão arterial, diminuindo assim a carga mundial dessa doença., Traducción oficial al español del artículo original en inglés efectuada por la Organización Panamericana de la Salud. En caso de discrepancia, prevalecerá la versión original en inglés. Wolters Kluwer Health, Inc. y sus sociedades no se hacen responsables de la exactitud de la traducción del original inglés ni de los eventuales errores que esta pueda contener. Cita del artículo original: Sharman JE, O'Brien E, Alpert B, Schutte AE, Delles C, Hecht Olsen M et al. Lancet commission on hypertension group position statement on the global improvement of accuracy standards for devices that measure blood pressure. J Hypertens. 2020:38:21-29.doi: https://doi. org/10.1097/HJH.0000000000002246, Ciencias Médicas y de la Salud

The Lancet Commission on Hypertension identified that a key action to address the worldwide burden of high blood pressure (BP) was to improve the quality of BP measurements by using BP devices that have been validated for accuracy. Currently, there are over 3 000 commercially available BP devices, but many do not have published data on accuracy testing according to established scientific standards. This problem is enabled through weak or absent regulations that allow clearance of devices for commercial use without formal validation. In addition, new BP technologies have emerged (e.g. cuffless sensors) for which there is no scientific consensus regarding BP measurement accuracy standards. Altogether, these issues contribute to the widespread availability of clinic and home BP devices with limited or uncertain accuracy, leading to inappropriate hypertension diagnosis, management and drug treatment on a global scale. The most significant problems relating to the accuracy of BP devices can be resolved by the regulatory requirement for mandatory independent validation of BP devices according to the universally-accepted International Organization for Standardization Standard. This is a primary recommendation for which there is an urgent international need. Other key recommendations are development of validation standards specifically for new BP technologies and online lists of accurate devices that are accessible to consumers and health professionals. Recommendations are aligned with WHO policies on medical devices and universal healthcare. Adherence to recommendations would increase the global availability of accurate BP devices and result in better diagnosis and treatment of hypertension, thus decreasing the worldwide burden from high BP.A Comissão Lancet sobre Hipertensão Arterial identificou que uma iniciativa central para enfrentar a carga mundial da hipertensão arterial seria a melhoria na qualidade da mensuração da pressão arterial pelo uso aparelhos de pressão arterial validados quanto à acurácia. Atualmente, existem mais de 3 000 aparelhos de pressão arterial disponíveis comercialmente; entretanto, muitos não têm dados publicados sobre testes de acurácia realizados de acordo com padrões científicos estabelecidos. Este problema resulta de regulamentação fraca ou inexistente, o que permite a aprovação para uso comercial de dispositivos sem validação formal. Além disso, surgiram novas tecnologias de mensuração da pressão arterial (por exemplo, sensores sem algemas) sem consenso científico quanto aos padrões de acurácia. No conjunto, essas questões contribuem para a oferta generalizada de dispositivos de pressão arterial clínica e domiciliar com acurácia limitada ou incerta, levando a diagnóstico, gerenciamento e tratamento inadequados da hipertensão em escala global. Os problemas mais significativos relacionados com a acurácia dos dispositivos de pressão arterial podem ser resolvidos por regulamentação que imponha a obrigatoriedade de validação independente dos aparelhos de pressão arterial, de acordo com a norma universalmente aceita pela Organização Internacional de Normalização. Esta é uma recomendação fundamental para a qual existe uma necessidade internacional urgente. Outras recomendações essenciais incluem o desenvolvimento de padrões de validação especificamente para novas tecnologias de mensuração da pressão arterial e listas

The Lancet Commission on Hypertension identified that a key action to address the worldwide burden of high blood pressure (BP) was to improve the quality of BP measurements by using BP devices that have been validated for accuracy. Currently, there are over 3 000 commercially available BP devices, but many do not have published data on accuracy testing according to established scientific standards. This problem is enabled through weak or absent regulations that allow clearance of devices for commercial use without formal validation. In addition, new BP technologies have emerged (e.g. cuffless sensors) for which there is no scientific consensus regarding BP measurement accuracy standards. Altogether, these issues contribute to the widespread availability of clinic and home BP devices with limited or uncertain accuracy, leading to inappropriate hypertension diagnosis, management and drug treatment on a global scale. The most significant problems relating to the accuracy of BP devices can be resolved by the regulatory requirement for mandatory independent validation of BP devices according to the universally-accepted International Organization for Standardization Standard. This is a primary recommendation for which there is an urgent international need. Other key recommendations are development of validation standards specifically for new BP technologies and online lists of accurate devices that are accessible to consumers and health professionals. Recommendations are aligned with WHO policies on medical devices and universal healthcare. Adherence to recommendations would increase the global availability of accurate BP devices and result in better diagnosis and treatment of hypertension, thus decreasing the worldwide burden from high BP.

Copyright © 2018 Wolters Kluwer Health, Inc., and American Heart Association, Inc. This article has been copublished in Hypertension. In the last 30 years, several organizations, such as the US Association for the Advancement of Medical Instrumentation (AAMI), the British Hypertension Society, the European Society of Hypertension (ESH) Working Group on Blood Pressure (BP) Monitoring and the International Organization for Standardization (ISO) have developed protocols for clinical validation of BP measuring devices. However, it is recognized that science, as well as patients, consumers and manufacturers would be best served if all BP measuring devices were assessed for accuracy according to an agreed single validation protocol that had global acceptance. Therefore, an international initiative was taken by AAMI, ESH and ISO experts who agreed to develop a universal standard for device validation. This statement presents the key aspects of a validation procedure, which were agreed by the AAMI, ESH and ISO representatives as the basis for a single universal validation protocol. As soon as the AAMI/ESH/ISO standard is fully developed, this will be regarded as the single universal standard and will replace all other previous standards/protocols.

Objectives This study describes the development of a new digital sphygmocorder (DS-II), which allows the digital recording and playback of the Korotkoff sounds, together with cuff pressure waveform, and its performance in a pilot validation study. Materials and methods A condenser microphone and stethoscope head detect Korotkoff sounds and an electronic chip, dedicated to audio-signal processing, is used to record high-quality sounds. Systolic and diastolic blood pressure (SBP/DBP) are determined from the recorded signals with an automatic beat detection algorithm that displays the cuff pressure at each beat on the monitor. Recordings of Korotkoff sounds, with the cuff pressure waveforms, and the simultaneous on-site assessments of SBP/DBP were performed during 100 measurements in 10 individuals. The observers reassessed the recorded signals to verify their accuracy and differences were calculated. Results The features of the high-fidelity DS-II, the technical specifications and the assessment procedures utilizing the playback software are described. Interobserver absolute differences (mean±SD) in measurements were 0.7±1.1/1.3±1.3 mmHg (SBP/DBP) with a mercury sphygmomanometer and 0.3±0.9/0.8±1.2 mmHg with the DS-II. The absolute DS-II mercury sphygmomanometer differences were 1.3±1.9/1.5±1.3 mmHg (SBP/DBP). Conclusion The high-fidelity DS-II device presents satisfactory agreement with simultaneous measurements of blood pressure with a mercury sphygmomanometer. The device will be a valuable methodology for validating new blood pressure measurement technologies and devices.

The diagnosis and management of hypertension is dependent on the accuracy of blood pressure measurement which, in turn, demands that the devices used for measurement are accurate. Regrettably, this is often not the case and there is a need, therefore, for validation procedures to ensure that devices on the market are accurate and reliable. All aspects of blood pressure device validation are reviewed in this chapter. The different validation protocols and their development are outlined, namely the Association for the Advancement of Medical Instrumentation (AAMI) and the International Standards Organisation (ISO) standards, the British Hypertension Society (BHS) protocols and the International Protocols of the European Society of Hypertension (ESH). The ways in which these protocols might be harmonised and improved is discussed. Manufacturer obligations and consumer requirements are given thoughtful consideration, and finally, the need for a unified approach to the evaluation of blood pressure measuring devices is emphasised.

BACKGROUND Ambulatory blood pressure measurement (ABPM) is being used increasingly in clinical practice. One previous study has shown that there can be considerable variance between expert observers in the interpretation of ABPM data. The purpose of this study was to show whether computer-generated reports with the dablABPM system would provide more consistency in the interpretation of data than reports from expert observers. METHODS Twenty-six international experts in hypertension were invited to participate and 17 agreed to do so. Twelve ABPMs generated by the Spacelabs device that were considered representative of the patterns likely to be seen in practice were sent to each participant for reporting. The corresponding dabl reports with an automatic interpretation were generated according to the European Society of Hypertension guideline for comparison with the observer reports. Each of the observer-interpreted Spacelabs reports for the 12 ABPM patterns were coded, analysed and compared with the automatically interpreted dablABPM reports. Both sets of data were analysed for interobserver variability, observer v dablABPM consistency and the time taken for observer reportage. The main analysis determined issues of definite disagreement, namely the presence or absence of nocturnal dipping. Further analysis determined the presence or absence of white-coat phenomena and the severity of hypertension. RESULTS Incorrect diagnoses were made in 13 instances. White-coat hypertension and white-coat effect, although obvious in many instances, were not identified in five ABPMs; the severity of hypertension was not reported in four ABPMs; the severity of nocturnal hypertension was not diagnosed in one ABPM by nine experts and isolated diastolic hypertension was not identified by six experts in two ABPMs. CONCLUSION This study provides evidence to show that observer variance in reporting ABPMs is common even among experts and that computer-generated interpretative reports of ABPM data improve the diagnostic decisions based on the data generated by 24-h blood pressure recording.

Objective To perform a systematic review of validation studies of blood pressure measuring devices done using the European Society of Hypertension International Protocol (ESH-IP) since its publication in 2002. Methods Major aspects of ESH-IP studies are described. A review of the ESH-IP performance, problems and violations in its application, and the effect of applying several more stringent validation criteria in an ESH-IP revision is carried out. Results From January 2002 to June 2009, 104 validation studies had been conducted using the ESH-IP, 36 using the British Hypertension Society protocol and 28 using the US Association for the Advancement of Medical Instrumentation protocol. Among 78 studies reported up to June 2008, in 66 (85%) the tested device has passed the ESH-IP. In 19 validations a modification of the ESH-IP was performed to adapt for specific study needs (population or device). Protocol violations of the ESH-IP were identified in 23 studies (eight major violations). A test of several arbitrarily chosen changes in the ESH-IP validation criteria applied in the published studies showed the phase 2.1 criterion (BP differences ≤15 mmHg) and the phase 2.2 criteria to be the more stringent. Conclusion The ESH-IP has succeeded in expanding the validation procedure worldwide by three to four-fold compared with the period before its publication. There is a need for protocol revision aiming to address issues that appeared in published studies, prevent protocol violations, and ensure complete data reporting. Standardization of the ESH-IP validation studies' report and application of more stringent criteria should be considered.

Ambulatory blood pressure monitoring (ABPM) accurately classifies blood pressure (BP) status but its impact on the prevalence and control of hypertension is little known. The authors conducted a cross‐sectional study in 2012 among 1047 individuals 60 years and older from the follow‐up of a population cohort in Spain. Three casual BP measurements and 24‐hour ABPM were performed under standardized conditions. Approximately 68.8% patients were hypertensive based on casual BP (≥140/90 mm Hg or current BP medication use) and 62.1% based on 24‐hour ABPM (≥130/80 mm Hg or current BP medication use) (P=.009). The proportion of patients with treatment‐eligible hypertension who met BP goals increased from 37.4% based on the casual BP target to 54.1% based on the 24‐hour BP target (absolute difference, 16.7%; P

Background 24-h ambulatory blood pressure measurement (ABPM) is now recognized as being indispensable in the diagnosis and management of hypertension. The technique must, therefore, be made available in primary care, but in doing so it must be recognized that unfamiliarity with the technique may lead to misinterpretation of data. Objective To facilitate the wider application of ABPM, especially in primary care, we examined the features that would facilitate the development of a standardized user-friendly software program for the presentation, analysis and interpretation of data. Methods and Results The following features were considered essential to any software program for ABPM: standardized plots of 24-h profiles; computer interpretation of ABPM data and patterns; a user-friendly one-page report, flexible statistical analysis, and the facility to group data and to export data for audit and research analysis. The dabl®ABPM program incorporating these features was introduced into the Blood Pressure Unit, Beaumont Hospital in 2000 and has been used in over 15 000 ABPM recordings. The program is now being used widely in general practice and specialized centres. Conclusions It is feasible to design a software program to provide a standardized plotting format for ABPM, a basic analysis of data for day-to-day clinical work, or elaborate analyses for research, and an interpretative report to assist diagnosis and to provide an educational process for doctors and nurses not familiar with the technique.

Ambulatory blood pressure monitoring and 24-h blood pressure control as predictors of outcome in treated hypertensive patients

With the introduction of 24h ambulatory blood pressure monitoring into clinical practice a vast market for ambulatory blood pressure monitoring devices has been created. To satisfy this market manufacturers are producing an array of ambulatory blood pressure monitoring devices. There is no obligation on manufacturers to have such devices validated independently, even though two national protocols, one from the British Hypertension Society (BHS) and the other from the Association for the Advancement of Medical Instrumentation (AAMI), call for independent validation and state the means of doing so. However, many factors can influence the validation procedure. They include compliance to the protocol being employed ; the accuracy of the standard ; establishing precisely the model being validated ; the influences of blood pressure level, age and exercise on device accuracy ; the provisions necessary for special populations, such as pregnant women, the elderly and children ; the influence of oscillometric versus Korotkoff sound detection and electrocardiographic gating on comparative measurements ; the assessment of performance as distinct from accuracy ; and the relevance of general factors, such as the algorithm being employed and computer compatibility. Forty-three ambulatory blood pressure monitoring devices have been marketed for ambulatory blood pressure measurement and of those only 18 have been validated according to either the BHS or the AAMI protocol. The influence of the factors listed above on the validation studies of those devices will be considered and the relevance of validation procedures to the clinical use of ambulatory blood pressure monitoring devices will be discussed.

Objective: To delineate more precisely an operational threshold for making clinical decisions based on ambulatory blood pressure (ABP) measurement by studying the ABP in subjects who were diagnosed as either normotensive or hypertensive by conventional blood pressure (CBP) measurement. Subjects: Twenty-four research groups recruited 7069 subjects. Of these, 4577 were normotensive (systolic CBP ≤ 140 mmHg and diastolic CBP ≤ 90 mmHg) and 1773 were hypertensive (systolic CBP ≥ 160 mmHg and/or diastolic CBP ≥ 90 mmHg). Of the latter, 1324 had systolic and 1310 had diastolic hypertension. Results: Ninety-five percent of the normotensive subjects had a 24-h ABP below (systolic and diastolic, respectively) 133 and 82 mmHg. Of the patients with systolic hypertension, 24% had a 24-h systolic ABP of Conclusion: The ABP distributions of the normotensive subjects included in the present international database were not materially different from those in previous reports in the literature. One-fifth to more than one-third of the hypertensive patients had an ABP which was below the 95th centile of the ABP in normotensive subjects, but this proportion decreased if the hypertensive patients had shown a higher CBP upon repeated measurement. The prognostic implications of elevated CBP in the presence of normal ABP remain to be determined.

We combined a database of paired blood pressure measurements taken using the Hawksley random-zero sphygmonanometer and a standard mercury sphygmomanometer and a database of paired measurements made on a SpaceLabs 90202 ambulatory blood pressure recorder and standard sphygmomanometer to determine how the SpaceLabs 90202 would have fared if it had been assessed against the Hawksley random-zero sphygmomanometer instead of a standard sphygmomanometer. The pooled database contained 255 triplicate readings. Using the standard sphygmomanometer as gold standard, the Spacelabs had a median error of 2 mm/Hg for both systolic and diastolic. Against the Hawksley random-zero sphygmomanometer, median error was -3 mm systolic and -6 mm diastolic. The proportion of errors10 mm rose from 11% (systolic) and 9% (diastolic) with the standard sphygmomanometer to 16% and 29% with the Hawksley random-zero sphygmomanometer. Because it underestimates systolic and diastolic pressures, the use of the Hawksley random-zero sphygmomanometer as a gold standard may have resulted in misleading conclusions about performance of some automated BP recorders.

Since 2002 when the European Society of Hypertension International Protocol (ESH-IP) was published it has become the preferred protocol for validating blood pressure monitors worldwide. In 2010, a revised version of the ESH-IP with more stringent criteria was published. This study assesses the impact of applying the revised ESH-IP criteria.A systematic literature review of ESH-IP studies reported between 2002 and 2010 was conducted. The impact of applying the ESH-IP 2010 criteria retrospectively on the data reported in these studies was investigated. The performance of the oscillometric devices in the last decade was also investigated on the basis of the ESH-IP criteria.Among 119 published studies, 112 with sufficient data were analyzed. According to ESH-IP 2002, the test device failed in 19 studies, whereas by applying the ESH-IP 2010 criteria in 28 additional studies increased the failure rate from 17 to 42%. Of these 28 studies, in 20 (71%) the test device failed at part 1 (accuracy per measurement) and in 22 (79%) at part 2 (accuracy per subject). Most of the failures involved the '5 mmHg or less' criterion. In the last decade there has been a consistent trend toward improved performance of oscillometric devices assessed on the basis of the ESH-IP criteria.This retrospective analysis shows that the stricter revised ESH-IP 2010 criteria will noticeably increase the failure rate of devices being validated. Oscillometric devices are becoming more accurate, and the revised ESH-IP by acknowledging this trend will allow more accurate devices to enter the market.

Validation of blood pressure measuring devices is a relatively new field of research. There are two national protocols for validating blood pressure measuring devices: the protocol of the American Association for the Advancement of Medical Instrumentation (AAMI) and the protocol of the British Hypertension Society (BHS), each of which has recently been revised. 19 blood pressure measuring devices have been validated according to one or both of these protocols. These protocols have been beneficial in drawing attention to the potential inaccuracy of blood pressure measuring systems, they permit comparison between devices and they have brought manufacturers of blood pressure measuring devices into closer contact with the profession. There are some inherent weaknesses in both protocols which include the fallibility of the 'gold standard', the lack of provision for validation in special circumstances and in special groups, such as the elderly and pregnant women, and failure to allow for deteriorating accuracy with higher pressure levels. The revised BHS protocol attempts to redress these deficiencies.

The management of high blood pressure (BP) is particularly inadequate in low-income countries, where the unavailability of a reliable, durable, and affordable BP-measurement device is a major obstacle to accurate diagnosis. Recognizing this, a World Health Organization committee was established to correct this deficiency by influencing manufacturers to produce a device according to predetermined criteria and to demonstrate the suitability of the device for low resource settings. A device, which fulfilled stipulated criteria in being inexpensive, semiautomated, and solar powered, was validated according to the International Protocol of the European Society of Hypertension; it was then subjected to field testing in 716 subjects from 2 centers in Uganda and 1 in Zambia. The Omron HEM-SOLAR having previously fulfilled accuracy criteria of the International Protocol for both systolic blood pressure (SBP) and diastolic blood pressure (DBP), fulfilled criteria for SBP, but not for DBP, when revalidated. In field testing, average SBPs and DBPs were 120.5±21.6/74.6±13.8 mm Hg and 122.3±21.8/71.2±14.0 mm Hg, respectively, with the auscultatory technique and the Omron HEM-SOLAR, respectively. Between-device agreement in defining SBP was 93.7%. The Omron HEM-SOLAR was favored over the mercury sphygmomanometer by both patients and investigators. In summary, considering the accuracy, robustness, relatively low cost, operational simplicity, and advantages such as solar power, the Omron HEM-SOLAR is likely to be a valuable device for improving BP measurement in low-resource settings with nonphysician health workers.

The Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland, dabl Ltd., Blackrock Co., Dublin, Ireland, Hypertension Center, Third University Department of Medicine, Sotiria Hospital, Athens, Greece, Istituto Scientifico Ospedale San Luca, IRCCS, Instituto Auxologico Italiano, Milan, Italy, Societe Francaise d’Hypertension Arterielle, Filiale de la Societe Francaise de Cardiolgie, Paris, France, The Department of Clinical Pharmacology and Therapeutics, Tohoku University Graduate School of Pharmaceutical Science and Medicine, Sendai, Japan, Centre for Epidemiological Studies and Clinical Trials, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China, University Clinic Bonn, Department of Internal Medicine, Bonn, Germany and Guy’s and St Thomas’ Hospitals, London, UK

This cross-sectional study investigated whether the technique of blood pressure measurement used (conventional sphygmomanometry vs. ambulatory monitoring) affects the relation between blood pressure and both age and body mass index. Two independent data sets were analyzed. The first comprised 328 subjects (48% men) drawn from the population of a small Belgian town, and the second comprised 776 Irish bank employees (51% men). Age ranged from 17 years to 81 years, and body mass index (weight (kg)/height (m)2) ranged from 16.6 to 40.2. Twenty-four-hour ambulatory blood pressure was lower than blood pressure measured by a nurse in both the Belgian population sample (118/71 mmHg vs. 122/73 mmHg) and the Irish employees (118/72 mmHg vs. 119/76 mmHg). When blood pressure was measured by an observer, the well-established relations between systolic and diastolic blood pressure and both age and body mass index were evident. When the analyses were repeated using 24-hour measurements, the increment (cross-sectionally assessed) in blood pressure with age was weaker, especially in young and middle-aged subjects (20-60 years), while the increase in blood pressure with body mass index was also reduced. The within-subject differences between the conventional and ambulatory blood pressure measurements increased with older age and greater body mass index. Several other relations with blood pressure as the response variable may require revision in light of the present findings.

Results of the Anglo-Scandinavian cardiac outcomes trial-blood pressure lowering arm (ASCOT-BPLA) showed significantly lower rates of coronary and stroke events in individuals allocated an amlodipine-perindopril combination drug regimen than in those allocated an atenolol-thiazide combination drug regimen. The aims of the ambulatory blood pressure (ABP) substudy of ASCOT were to examine the impact of the two blood pressure (BP)- lowering regimens on ambulatory pressures, test to what extent the between-treatment differences in cardiovascular outcome could be attributed to differences in ABP and assess whether ABP provides predictive information additional to that of clinic blood pressure (CBP) in treated hypertensive patients.One thousand, nine hundred and five patients from four ASCOT centres had repeated ABPs performed over a median follow-up period of 5.5 years. As in the whole ASCOT population, CBP values were lower in amlodipine-perindopril-treated patients compared with those treated with atenolol-thiazide [between-regimen difference [95% confidence intervals (CIs)]]: [-1.5 (-2.4 to -0.5)/-1.2 (-1.8 to +0.5) mmHg]. Daytime BP during follow-up was higher in patients treated with amlodipine-perindopril therapy [+1.1 (0.1-2.1)/+1.6 (0.8-2.3) mmHg]; night-time systolic, but not diastolic BP, was lower in patients treated with amlodipine-perindopril therapy [-2.2 (-3.4 to +0.9)/+0.8 (0.0-1.6) mmHg]. The relative risk of a cardiovascular event associated with a 1 SD increment in accumulated mean BP was 1.35 (1.18-1.53) for clinic systolic BP, 1.30 (1.14-1.49) for daytime systolic BP and 1.42 (1.24-1.62) for night-time systolic BP. With adjustment for baseline variables, treatment regimen and clinic systolic BP, the hazard ratios were 1.17 (1.00-1.36) and 1.25 (1.08-1.47) for daytime and night-time systolic BP, respectively. The between-regimen adjusted hazard ratio for cardiovascular events (amlodipine-perindopril therapy versus atenolol-thiazide therapy) was 0.74 (0.55-1.01) and increased to 0.81 (0.60-1.10) after further adjustment for clinic systolic BP. Further, adjustment for night-time systolic BP increased the hazard ratio to 0.85 (0.62-1.16).The amlodipine-perindopril and atenolol-thiazide regimens had different effects on daytime and night-time ABP, which may have contributed to the lower rates of events in patients treated with amlodipine-perindopril therapy. Both CBP and ABP were significantly associated with rates of cardiovascular events. ABP nocturnal pressures provided complimentary and incremental utility over CBP in the prediction of cardiovascular risk in treated hypertensive patients. These data support the use of ABP to assess the effect of antihypertensive treatment in clinical practice.

Inaccurate blood pressure measurement leads inevitably to the inappropriate diagnosis and treatment of hypertension with resultant disadvantages for patients. Despite the serious consequences of inaccurate measurement of blood pressure the fact is that there are many inaccurate devices in the market and many have not been validated independently for accuracy. To overcome this deficiency, state-of-the-market papers have been published over the past decade. These papers, however, are limited in their availability to the wide range of potential purchasers of blood pressure measuring devices and such papers are often out-of-date by the time of publication. The dableducational website was founded in 2003 to provide regularly updated evidence-based information on blood pressure measuring devices on the internet to all would-be purchasers of blood pressure measuring devices. Since its foundation, the dableducational website has received in excess of 2 million visits; it is used by 1200 organizations in more than 105 countries worldwide, and receives an average of 160,000 visits monthly with a high percentage take down rate. In addition, the website provides a library resource with over 450 papers, and a device equivalence procedure for manufacturers.

With the increasing manufacture of expensive systems for the measurement of ambulatory blood pressure there is a need for potential purchasers to be able to satisfy themselves that the systems have been evaluated according to agreed criteria. The British Hypertension Society has, therefore, drawn up

Seven models, available commercially for the self-measurement of blood pressure, were subjected to a validation procedure in which three devices of each model were tested by observers who were trained to a high standard of accuracy. The models were the Omron HEM-400C, the Philips HP5308, the Healthcheck 'Cuffless' CX-5 060020, the Nissei Analogue Monitor, the Philips HP5306/B, the Systema Dr MI-150 and the Fortec Dr MI-100. The validation programme had a number of unique features which included assessment of interdevice variability before and after 1 month of home use, and a new form of analysis, which we term 'clinical', based on the likely influence of three grades of device inaccuracy on patient management. In the main validation phase, one device of each model was compared with simultaneous measurements made by two 'blinded' observers using a standard mercury sphygmomanometer (PyMaH Corporation, New Jersey, USA) in the same arm in 85 subjects with a wide range of blood pressures. Three models (the Healthcheck 'Cuffless' CX-5 060020, the Systema Dr MI-150 and the Fortec Dr MI-100) failed the interdevice variability tests and did not reach the main validation test. Two models (the Omron HEM-400C and the Philips HP5306/B) failed on the criteria set down by the American National Standard for Electronic or Automated Sphygmomanometers, as well as the 'clinical' criteria. The remaining two models (the Nissei Analogue Monitor and the Philips HP5308) were acceptable for the measurement of systolic blood pressure by both methods of analysis but failed in the 'clinical' analysis for diastolic blood pressure. The mercury sphygmomanometer was comfortably within the criteria for both methods of analysis.

With the increasing marketing of automated and semiautomated devices for the measurement of blood pressure, there is a need for potential purchasers to be able to satisfy themselves that such devices have been evaluated according to agreed-upon criteria (1). With this need in mind, the Association for the Advancement of Medical Instrumentation (AAMI) published a standard for electronic or aneroid sphygmomanometers in 1987 (2), which included a protocol for the evaluation of the accuracy of devices; this was followed in 1990 by the protocol of the British Hypertension Society (BHS) (3). Both protocols were revised in 1993 (4,5). These protocols, which differed in detail, had a common objective, namely the standardization of validation procedures to establish minimum standards of accuracy and performance and to facilitate comparison of one device with another (6).

Manufacturers of blood pressure measuring devices that have previously been successfully validated for accuracy may make modifications to a device, which do not affect its measurement accuracy and should not require further validation. In this paper the procedure for manufacturers to declare the equivalence of a modified device with a device that has been validated earlier is described.

We hypothesized that the dynamic relation between diastolic and systolic blood pressure over 24 hours provides a measure of arterial stiffness and might, therefore, predict cardiovascular mortality over and above pulse pressure. At baseline, while not on antihypertensive medication, 11 291 patients (mean age, 54.6 years; 5965 women) underwent ambulatory blood pressure monitoring. Using all of the blood pressure readings, we plotted diastolic against systolic blood pressure from each individual and calculated the regression slope. The ambulatory arterial stiffness index (AASI) was defined as 1 minus this regression slope. Over a median follow-up of 5.3 years, 566 cardiovascular deaths occurred, including 151 from stroke and 358 from cardiac disorders. Before and after adjustment for other cardiovascular risk factors, AASI and pulse pressure significantly predicted total cardiovascular mortality. AASI was a stronger predictor than pulse pressure for stroke (mutually adjusted relative hazard ratios for 1 SD increase, 1.21 versus 1.04; P =0.02 versus 0.66) with the opposite trend for cardiac mortality (relative hazard ratios, 1.03 versus 1.21; P =0.63 versus 0.002). In subjects with normal daytime ambulatory blood pressure (P =0.04 versus 0.70) and of stroke mortality (1.81 versus 1.12; P =0.007 versus 0.58), whereas neither independently predicted cardiac mortality (1.11 versus 0.89; P =0.47 versus 0.40). AASI is a novel measure of arterial stiffness, which can be readily determined from ambulatory blood pressure recordings and which independently predicts cardiovascular mortality, even in normotensive subjects.

The purpose of this study was to determine if ambulatory blood pressure measurement predicted total and cardiovascular mortality over and beyond clinic blood pressure measurement and other cardiovascular risk factors; 5292 untreated hypertensive patients referred to a single blood pressure clinic who had clinic and ambulatory blood pressure measurement at baseline were followed up in a prospective study of mortality outcome. Multiple Cox regression was used to model time to total and cause-specific mortality for ambulatory blood pressure measurement while adjusting for clinic blood pressure measurement and other risk factors at baseline. There were 646 deaths (of which 389 were cardiovascular) during a median follow-up period of 8.4 years. With adjustment for gender, age, risk indices, and clinic blood pressure, higher mean values of ambulatory blood pressure were independent predictors for cardiovascular mortality. The relative hazard ratio for each 10-mm Hg increase in systolic blood pressure was 1.12 (1.06 to 1.18; P P P =NS) for daytime and 1.09 (1.04 to 1.13; P

BACKGROUND: The prevalence of white-coat hypertension (WCH) is considerable in patients referred with elevated office blood pressure. Failure to recognise this phenomenon can lead to the inappropriate use of antihypertensive medications. We undertook this study to determine the profile of patients with WCH. METHODS: Baseline clinic and daytime ambulatory blood pressures were available from 5716 patients referred over a 22-year period. Individuals were considered to have WCH if they had an elevated clinic blood pressure measurement greater than 140/90 mmHg and normal daytime mean ambulatory blood pressure. Mean age was 53.6 years and 53.2% were female. RESULTS: The overall prevalence of white-coat hypertension was 15.4%. A higher prevalence was seen amongst older adults, females, and non-smokers. CONCLUSION: Multivariate logistic regression analysis confirmed these characteristics as independent predictors of WCH. ispartof: Blood pressure monitoring vol:9 issue:6 pages:307-9 ispartof: location:FRANCE, Paris status: published

Background It is now accepted that blood pressure measuring devices should be subjected to an independent evaluation of their accuracy before they are marketed for clinical use. The results of validation of the ROSSMAX Blood Pressure Measuring Monitor for self-measurement according to the European Society of Hypertension International Protocol for Validation of Blood Pressure Measuring Devices in Adults are presented in this paper. Population Thirty-three subjects were recruited from among staff and patients at Beaumont Hospital, Dublin, Ireland. Methods The ROSSMAX monitor was connected to the Sphygmocorder, an audiovisual system for validation, which records blood pressure on tape and video for later analysis. Nine sequential same-arm measurements between the device and a standard mercury sphygmomanometer were recorded using the Sphygmocorder. Results In phase 1, the ROSSMAX monitor produced 21 measurements within 5 mmHg, 31 within 10 mmHg and 38 within 15 mmHg for systolic blood pressure (SBP), and 36 within 5 mmHg, 43 within 10 mmHg and 45 within 15 mmHg for diastolic blood pressure (DBP). The mean differences were -5.6 (10.2) [mean (SD)] mmHg for SBP and -0.5 (4.5) mmHg for DBP. The ROSSMAX monitor failed to meet any of the criteria for SBP but comfortably passed all of the criteria for DBP. In phase 2.1, the ROSSMAX monitor had 51 measurements within 5 mmHg, 73 within 10 mmHg and 86 within 15 mmHg for SBP, and 71 measurements within 5 mmHg, 93 within 10 mmHg and 98 within 15 mmHg for DBP. The mean differences were -4.5. (9.5) mmHg for SBP and -1.8 (5.0) mmHg for DBP. The ROSSMAX monitor failed to meet any of the criteria for SBP but comfortably passed all of the criteria for DBP. In phase 2.2, 16 subjects had at least two of the differences lying within 5 mmHg and 10 subjects had no differences within 5 mmHg for SBP; 26 subjects had at least two of the differences falling within 5 mmHg and three subjects no differences within 5 mmHg for DBP. The ROSSMAX monitor failed to meet the criteria for SBP but passed the criteria for DBP. Conclusions The ROSSMAX monitor cannot be recommended for clinical use in an adult population because it records SBP inaccurately.

BACKGROUND It is now accepted that blood pressure measuring devices should be subjected to an independent evaluation of their accuracy before they are marketed for clinical use. The results of validation of the TONOPORT V blood pressure monitor for the measurement of ambulatory blood pressure according to the European Society of Hypertension International Protocol for Validation of Blood Pressure Measuring Devices in Adults are presented in this paper. POPULATION Thirty-three subjects were recruited from among staff and patients at Beaumont Hospital, Dublin, Ireland. METHODS The TONOPORT V monitor was connected to the Sphygmocorder, an audiovisual system for validation, which records blood pressure on tape and video for later analysis. Nine sequential same-arm measurements between the device and a standard mercury sphygmomanometer were recorded using the Sphygmocorder. RESULTS In phase 1, the TONOPORT V monitor produced 28 measurements within 5 mmHg, 37 within 10 mmHg and 40 within 15 mmHg for systolic blood pressure (SBP), and 26 within 5 mmHg, 38 within 10 mmHg and 44 within 15 mmHg for diastolic blood pressure (DBP). The mean differences were -2.2 (8.6) [mean (SD)] mmHg for SBP and +0.5 (7.2) mmHg for DBP. The TONOPORT V monitor passed all the criteria for both SBP and DBP. In phase 2.1, the TONOPORT V monitor had 56 measurements within 5 mmHg, 78 within 10 mmHg and 88 within 15 mmHg for SBP, and 60 measurements within 5 mmHg, 83 within 10 mmHg and 97 within 15 mmHg for DBP. The mean differences were -1.4 (8.7) mmHg for SBP and -0.2 (6.8) mmHg for DBP. The TONOPORT V monitor passed the criteria for DBP but failed to meet any of the criteria for SBP. In phase 2.2, 19 subjects had at least two of the differences within 5 mmHg and six subjects had no differences within 5 mmHg for SBP, and 22 subjects had at least two of the differences within 5 mmHg and six subjects no differences within 5 mmHg for DBP. The TONOPORT V monitor failed to meet the criteria for SBP and for DBP. CONCLUSIONS The TONOPORT V monitor cannot be recommended for clinical use in an adult population because it records SBP inaccurately and because it records DBP inaccurately in an unacceptably high proportion of people.

BACKGROUND: Ambulatory blood pressure monitoring (ABPM) has proven to be a superior predictor of morbid events when compared to clinic or office blood pressure measurement (CBPM). The purpose of this study was to evaluate the predictive value of ABPM in a sample of 14 414 people referred for management of cardiovascular risk. METHODS: In this paper we describe the methodology required to examine mortality outcome in the absence of a national unique identifier. RESULTS: Using a computerized database of deaths we were able to establish that 1348 people had died by the end of the follow-up period (30 September 2002). Sixty-four percent of deaths were cardiovascular and in 207 subjects who had post-mortem examinations, 78% were cardiovascular. CONCLUSIONS: The accurate identification of the cause of death in a large population will allow comparison of the relative predictive power of APBM and CBPM in an Irish population. ispartof: Blood Pressure Monitoring vol:8 issue:4 pages:143-145 ispartof: location:ITALY, MILAN status: published

OBJECTIVE To investigate ambulatory blood pressure in elderly people, including 'old elderly' subjects, aged over 80 years. DESIGN Cross-sectional study of community-dwelling, elderly subjects. METHODS Subjects were healthy, self-caring, and living independently. Those who were taking medication affecting blood pressure were excluded. Conventional blood pressure was the mean of two measurements. Ambulatory blood pressure monitoring was performed using the SpaceLabs 90207 device. Daytime and night-time blood pressure were defined by fixed clock intervals. RESULTS Seventy-five 'young elderly', aged 60-79 years, (39 men, 36 women) and 81 'old elderly' aged 80 years and older (37 men, 44 women) underwent 24-h ambulatory blood pressure monitoring. Systolic blood pressure (SBP) was related to age, correlation coefficients between age and SBP were 0.31, 0.25 and 0.31, respectively, for conventional SBP, daytime SBP and night-time SBP (P < 0.01 for all). There was no correlation between age and diastolic blood pressure. Blood pressure levels were similar in men and women. Mean conventional blood pressure, daytime blood pressure and night-time blood pressure were found to be 149/81, 138/82 and 119/69 mmHg, respectively, in the 'young elderly' and 162/82, 147/83, and 133/71 mmHg, respectively, in the 'old elderly (P < 0.01 for SBP). The night : day SBP ratio was significantly higher in the 'old' elderly compared with the 'young' elderly (0.90 versus 0.86, respectively; P < 0.01). CONCLUSIONS Ambulatory blood pressure levels in healthy, community-dwelling 'old elderly' are higher than those reported for younger adults and reflect the prominent age-related rise in SBP associated with advanced old age. Advanced old age is associated with a diminished nocturnal dip in blood pressure.

Abstract —White coat hypertension (WCH) is common in referred hypertensive patients. Ambulatory blood pressure monitoring (ABPM) is not free from the white coat syndrome. We examined the use of the elevation of the first and last measurements of ABPM for diagnosis of WCH in a hypertensive population that had been referred to a hospital-based hypertension unit. Data were obtained on 1350 patients for clinic and ABPM parameters. WCH, as diagnosed by conventional clinic blood pressure (BP) measurement, was compared with a variety of alternative methods determined from ABPM. In all cases, mean daytime pressure was P P 1 +V 5 , 21±7 mV versus 18±6 mV). Elevation of BP above 140 mm Hg systolic or 90 mm Hg diastolic in the first or last hour of monitoring diagnoses patients with a white coat response in whom there is a higher BP profile than in patients with classic white coat response alone. We suggest, therefore, that this is a better measure of the white coat phenomenon.

To evaluate the Profilomat II monitor for ambulatory blood pressure measurement according to the protocols of the British Hypertension Society (BHS) and the Association for the Advancement of Medical Instrumentation (AAMI).The BHS protocol is divided into two parts. Part I, which is the part applicable to this study, comprises the main validation procedure and has five phases: before-use device calibration; static device validation; and report of evaluation.Three Profilomat II recorders passed the before-use device calibration test. They then entered the in-use (field) assessment phase during which the three recorders were each worn by ten subjects for 24-h, after which the calibration was again assessed. Since no difference in calibration testing was observed between the three devices, one was selected randomly and the main validation test was carried out in 85 subjects, who had a wide range of blood pressures, using the sphygmocorder. The results were analysed according to the BHS grading system from A to D. The data was also analysed according to the standard of the Association for the Advancement of Medical Instrumentation (AAMI) which stipulates that the mean difference between the test device and the standard shall be/= 5 mmHg with a standard deviation of/= 8 mmHg.The Profilomat II achieved a BHS grade C rating for systolic blood pressure and grade B for diastolic blood pressure; it satisfied the criteria for accuracy of the AAMI for diastolic but not systolic blood pressure. When the BHS and AAMI criteria were applied to tertiles of pressure (low pressure range130/80 mmHg, medium pressure range 130-160/80-100 mmHg, high pressure range160/100 mmHg), the Profilomat II was less accurate in the high pressure range, achieving a D/C grading, and failed the AAMI criteria for systolic and diastolic blood pressures. The mean and standard deviation of the first mercury sphygmomanometer measurements were 145+/-34/87+/- 20 mmHg. Subject acceptability was good and the manufacturers manual was satisfactory.On the basis of these results, the Profilomat II cannot be recommended for ambulatory blood pressure measurement in clinical practice where accurate measurements are required.

Abstract The introduction of 24-hour ambulatory blood pressure measurement into clinical practice created a large market for ambulatory blood pressure measurement devices. Forty-three such devices from 31 manufacturers or suppliers are now available to satisfy a market demand that is likely to increase. The aim of this article is to identify the devices available and then to examine critically any validation studies assessing accuracy and performance. Of the 43 devices available 18 have been validated according to the protocols of the Association for the Advancement of Medical Instrumentation (AAMI) or the British Hypertension Society (BHS) in 25 reported studies. In 9 of these studies the protocol was not adhered to, and the results, which are therefore questionable, are noted but not considered further. Fourteen devices were evaluated according to the accuracy criteria of both protocols, and of these 9 fulfilled the requirements. From this review of 43 devices on the market it may be concluded that, at the time of writing, there is published evidence for only 9 devices meeting the generally accepted AAMI and BHS criteria for accuracy and performance; these are the A&D TM-2420 models 6 and 7 and TM-2421, CH-Druck, Nissei ABPM DS-240, Profilomat, QuietTrak, and SpaceLabs SL-90202 and SL-90207.

With the introduction of 24 h ambulatory blood pressure monitoring into clinical practice a vast market for ambulatory blood pressure monitoring devices has been created. To satisfy this market manufacturers are producing an array of ambulatory blood pressure monitoring devices. There is no obligation on manufacturers to have such devices validated independently, even though two national protocols, one from the British Hypertension Society (BHS) and the other from the Association for the Advancement of Medical Instrumentation (AAMI), call for independent validation and state the means of doing so. However, many factors can influence the validation procedure. They include compliance to the protocol being employed; the accuracy of the standard; establishing precisely the model being validated; the influences of blood pressure level, age and exercise on device accuracy; the provisions necessary for special populations, such as pregnant women, the elderly and children; the influence of oscillometric versus Korotkoff sound detection and electrocardiographic gating on comparative measurements; the assessment of performance as distinct from accuracy; and the relevance of general factors, such as the algorithm being employed and computer compatibility. Forty-three ambulatory blood pressure monitoring devices have been marketed for ambulatory blood pressure measurement and of those only 18 have been validated according to either the BHS or the AAMI protocol. The influence of the factors listed above on the validation studies of those devices will be considered and the relevance of validation procedures to the clinical use of ambulatory blood pressure monitoring devices will be discussed.

Experience with the original protocols of the Association for the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS) for validating blood pressure has provided valuable insight into the methodological problems associated with device validation and has influenced both the BHS and the AAMI in revising their protocols.To review the revisions of the original BHS and AAMI protocols; to compare the protocols; and, using the BHS protocol as a framework for validation, to determine how it should be modified to a protocol that will fulfil the criteria of both the AAMI and the BHS.The revised protocols have many similarities but there are some important differences. These differences merit consideration so as to facilitate manufacturers seeking to validate devices for acceptance in both Europe and the United States. Of the two protocols, the BHS protocol is the more elaborate in that (1) it takes particular care to ensure that observers are trained to a very high standard, (2) it makes provision for special group validation and (3) it recommends in-use validation of all devices. By modifying the BHS protocol, it is possible to validate blood pressure measuring devices (ambulatory devices require special consideration) to satisfy the criteria of both protocols.

This study investigated the consistency of a reference frame for ambulatory pressure monitoring, which using various approaches was determined in two different populations. The two reference groups were 718 subjects randomly selected from the population and 895 bank employees. The reference values derived in these two groups were subsequently tested in 591 untreated hypertensive patients. The ambulatory pressures equivalent to a conventional pressure of 140 mmHg systolic and 90 mmHg diastolic were calculated by regression analysis in all subjects. In addition, in subjects who were normotensive by conventional sphygmomanometry, the mean +2 and +3 standard deviations and the 90th, 95th and 99th percentiles of the ambulatory measurements were determined. The distributions of the ambulatory measurements were similar in the two reference groups and the aforementioned parameters therefore agreed within 4 mmHg in the two populations. There was considerable overlap in the ambulatory pressures between the two reference groups and the hypertensive patients. Classification of the patients according to the means +3 standard deviations and the regression limits gave the same results because in both reference groups these boundaries approximated to each other within 1 mmHg. For the 24 h pressures in the population sample these boundaries were 140 mmHg systolic and 88 mmHg diastolic. Of the patients with systolic hypertension (or = 160 mmHg on conventional measurement), 39% had a 24 h systolic pressure of140 mmHg and of those with diastolic hypertension (or = 95 mmHg), 44% had a 24 h diastolic pressure of88 mmHg; if the corresponding boundaries derived in the bank employees (143/90 mmHg) were applied, these proportions were 47% and 44%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)